# US 8,999,048 B2 · Exhaust gas purifying apparatus for diesel engine

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 8,999,048 B2
- Document ID: US8999048B2
- Status: Granted
- Kind: B2
- Application number: 13/805,526
- Filed: 2011-05-20
- Published: 2013-04-18
- Granted: 2015-04-07
- Earliest claimed: 2010-06-25
- Assignees: Nissan Motor Co., Ltd.
- Applicants: Toru Nishizawa; Risa Yamamoto
- Inventors: Toru Nishizawa; Risa Yamamoto
- Web page: https://patentgrep.com/patent/US8999048B2

## CPC

- F01N 3/0238: {for regenerating during engine standstill}
- F02D 41/029: {the exhaust gas treating apparatus being a particulate filter}
- F02D 41/042: {for stopping the engine}
- F02N 11/0829: {related to special engine control, e.g. giving priority to engine warming-up or learning}
- F01N 3/021: by means of filters
- F02D 41/065: {at hot start or restart (F02D41/067 takes precedence)}
- F02D 41/1448: {the characteristics being an exhaust gas pressure}
- F02D 41/405: {with post injections}
- F02D 2200/0802: Temperature of the exhaust gas treatment apparatus
- F02M 26/05: High pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust system upstream of the turbine and reintroduced into the intake system downstream of the compressor
- F02N 2200/026: Catalyst temperature
- Y02T 10/40: Engine management systems
- F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16)
- F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W)
- F02N: STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR
- F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

An exhaust gas purifying apparatus for a diesel engine includes a diesel particulate filter (DPF) in an exhaust system in the diesel engine. The exhaust gas purifying apparatus is constructed to execute regeneration of the DPF by raising a temperature of the DPF in a case where a predetermined DPF regeneration condition is fulfilled, interrupt the regeneration of the DPF, execute idling stop, automatically restart the diesel engine and then restart the regeneration of the DPF, and when shifting to the idling operation is carried out during regeneration of the DPF, delay execution of the idling stop until a temperature of the DPF at a time at which the idling stop is started becomes not less than a temperature of the DPF at a time at which shifting to an idling operation is carried out even in a case where the predetermined idling stop condition is fulfilled.

## Claims

### Claim 1

An exhaust gas purifying apparatus for a diesel engine, the diesel engine conducting idling stop to automatically stop the diesel engine in a case where a predetermined idling stop condition is fulfilled, the exhaust gas purifying apparatus comprising:
a diesel particulate filter (DPF) disposed in an exhaust system in the diesel engine to trap a particulate matter in exhaust gas discharged from the diesel engine; and
a controller configured to control:
a DPF regeneration section to execute regeneration of the DPF by raising a temperature of the DPF in a case where a predetermined DPF regeneration condition is fulfilled;
a DPF regeneration interruption and restart section to interrupt the regeneration of the DPF, to execute idling stop, to automatically restart the diesel engine and then to restart the regeneration of the DPF; and
an idling stop delay section to delay execution of the idling stop until a temperature of the DPF at a time at which the idling stop is started becomes not less than a temperature of the DPF at a time at which shifting to an idling operation is carried out even in a case where the predetermined idling stop condition is fulfilled, when shifting to the idling operation is carried out during the regeneration of the DPF.

### Claim 2 (depends on 1)

The exhaust gas purifying apparatus as claimed in claim 1, further comprising a crystallization estimation section, the controller configured to control the crystallization estimation section to estimate a degree of crystallization of the particulate matter in the DPF which varies in accordance with an amount of heat to which the particulate matter trapped in the DPF is exposed,
wherein the controller is configured to control the idling stop delay section to delay the execution of the idling stop in a case where shifting to the idling operation is carried out during the regeneration of the DPF and the degree of crystallization of the particulate matter is less than a predetermined crystallization threshold value at which crystal growth of the particulate matter rapidly proceeds to thereby raise a temperature of the DPF.

### Claim 3 (depends on 2)

The exhaust gas purifying apparatus as claimed in claim 2, wherein the controller is configured to control the crystallization estimation section to estimate the degree of crystallization of the particulate matter in accordance with a temperature of the DPF such that as the temperature of the DPF becomes higher, the degree of crystallization of the particulate matter is increased.

### Claim 4 (depends on 2)

The exhaust gas purifying apparatus as claimed in claim 2, wherein the controller is configured to control the crystallization estimation section to estimate the degree of crystallization of the particulate matter in accordance with a fuel property such that as the fuel property is lighter, the degree of crystallization of the particulate matter is lowered.

### Claim 5 (depends on 2)

The exhaust gas purifying apparatus as claimed in claim 2, wherein in a case where the degree of crystallization of the particulate matter is not less than the predetermined crystallization threshold value when shifting to the idling operation is carried out during the regeneration of the DPF, the controller is configured to control the idling operation to be prolonged without starting the idling stop and to be continued until the temperature of the DPF is dropped to not more than a predetermined value.

### Claim 6 (depends on 5)

The exhaust gas purifying apparatus as claimed in claim 5, wherein the controller is configured to control an engine speed to be increased during the idling operation in a case where the degree of crystallization of the particulate matter is not less than the predetermined crystallization threshold value when shifting to the idling operation is carried out during the regeneration of the DPF.

### Claim 7 (depends on 5)

The exhaust gas purifying apparatus as claimed in claim 5, wherein the predetermined value is a temperature value at which the crystal growth of the particulate matter is suppressed.

### Claim 8 (depends on 3)

The exhaust gas purifying apparatus as claimed in claim 3, wherein the controller is configured to control the crystallization estimation section to estimate the degree of crystallization of the particulate matter in accordance with a fuel property such that as the fuel property is lighter, the degree of crystallization of the particulate matter is lowered.

### Claim 9 (depends on 3)

The exhaust gas purifying apparatus as claimed in claim 3, wherein in a case where the degree of crystallization of the particulate matter is not less than the predetermined crystallization threshold value when shifting to the idling operation is carried out during the regeneration of the DPF, the controller is configured to control the idling operation to be prolonged without starting the idling stop and to be continued until the temperature of the DPF is dropped to not more than a predetermined value.

### Claim 10 (depends on 4)

The exhaust gas purifying apparatus as claimed in claim 4, wherein in a case where the degree of crystallization of the particulate matter is not less than the predetermined crystallization threshold value when shifting to the idling operation is carried out during the regeneration of the DPF, the controller is configured to control the idling operation to be prolonged without starting the idling stop and to be continued until the temperature of the DPF is dropped to not more than a predetermined value.